/**
 * @file
 * Sockets BSD-Like API module
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 * Improved by Marc Boucher <marc@mbsi.ca> and David Haas <dhaas@alum.rpi.edu>
 *
 */

#include "lwip/opt.h"

#if LWIP_SOCKET /* don't build if not configured for use in lwipopts.h */

#include "lwip/sockets.h"
#include "lwip/api.h"
#include "lwip/sys.h"
#include "lwip/igmp.h"
#include "lwip/inet.h"
#include "lwip/tcp.h"
#include "lwip/raw.h"
#include "lwip/udp.h"
#include "lwip/tcpip.h"
#include "lwip/pbuf.h"
#if LWIP_CHECKSUM_ON_COPY
	#include "lwip/inet_chksum.h"
#endif

#include <string.h>

#define NUM_SOCKETS MEMP_NUM_NETCONN

/** Contains all internal pointers and states used for a socket */
struct lwip_sock {
	/** sockets currently are built on netconns, each socket has one netconn */
	struct netconn* conn;
	/** data that was left from the previous read */
	void* lastdata;
	/** offset in the data that was left from the previous read */
	u16_t lastoffset;
	/** number of times data was received, set by event_callback(),
	    tested by the receive and select functions */
	s16_t rcvevent;
	/** number of times data was ACKed (free send buffer), set by event_callback(),
	    tested by select */
	u16_t sendevent;
	/** error happened for this socket, set by event_callback(), tested by select */
	u16_t errevent;
	/** last error that occurred on this socket */
	int err;
	/** counter of how many threads are waiting for this socket using select */
	int select_waiting;
};

/** Description for a task waiting in select */
struct lwip_select_cb {
	/** Pointer to the next waiting task */
	struct lwip_select_cb* next;
	/** Pointer to the previous waiting task */
	struct lwip_select_cb* prev;
	/** readset passed to select */
	fd_set* readset;
	/** writeset passed to select */
	fd_set* writeset;
	/** unimplemented: exceptset passed to select */
	fd_set* exceptset;
	/** don't signal the same semaphore twice: set to 1 when signalled */
	int sem_signalled;
	/** semaphore to wake up a task waiting for select */
	sys_sem_t sem;
};

/** This struct is used to pass data to the set/getsockopt_internal
 * functions running in tcpip_thread context (only a void* is allowed) */
struct lwip_setgetsockopt_data {
	/** socket struct for which to change options */
	struct lwip_sock* sock;
#ifdef LWIP_DEBUG
	/** socket index for which to change options */
	int s;
#endif /* LWIP_DEBUG */
	/** level of the option to process */
	int level;
	/** name of the option to process */
	int optname;
	/** set: value to set the option to
	  * get: value of the option is stored here */
	void* optval;
	/** size of *optval */
	socklen_t* optlen;
	/** if an error occures, it is temporarily stored here */
	err_t err;
};

/** The global array of available sockets */
static struct lwip_sock sockets[NUM_SOCKETS];
/** The global list of tasks waiting for select */
static struct lwip_select_cb* select_cb_list;
/** This counter is increased from lwip_select when the list is chagned
    and checked in event_callback to see if it has changed. */
static volatile int select_cb_ctr;

/** Table to quickly map an lwIP error (err_t) to a socket error
  * by using -err as an index */
static const int err_to_errno_table[] = {
	0,             /* ERR_OK          0      No error, everything OK. */
	ENOMEM,        /* ERR_MEM        -1      Out of memory error.     */
	ENOBUFS,       /* ERR_BUF        -2      Buffer error.            */
	EWOULDBLOCK,   /* ERR_TIMEOUT    -3      Timeout                  */
	EHOSTUNREACH,  /* ERR_RTE        -4      Routing problem.         */
	EINPROGRESS,   /* ERR_INPROGRESS -5      Operation in progress    */
	EINVAL,        /* ERR_VAL        -6      Illegal value.           */
	EWOULDBLOCK,   /* ERR_WOULDBLOCK -7      Operation would block.   */
	EADDRINUSE,    /* ERR_USE        -8      Address in use.          */
	EALREADY,      /* ERR_ISCONN     -9      Already connected.       */
	ECONNABORTED,  /* ERR_ABRT       -10     Connection aborted.      */
	ECONNRESET,    /* ERR_RST        -11     Connection reset.        */
	ENOTCONN,      /* ERR_CLSD       -12     Connection closed.       */
	ENOTCONN,      /* ERR_CONN       -13     Not connected.           */
	EIO,           /* ERR_ARG        -14     Illegal argument.        */
	-1,            /* ERR_IF         -15     Low-level netif error    */
};

#define ERR_TO_ERRNO_TABLE_SIZE \
  (sizeof(err_to_errno_table)/sizeof(err_to_errno_table[0]))

#define err_to_errno(err) \
  ((unsigned)(-(err)) < ERR_TO_ERRNO_TABLE_SIZE ? \
    err_to_errno_table[-(err)] : EIO)

#ifdef ERRNO
	#ifndef set_errno
		#define set_errno(err) errno = (err)
	#endif
#else /* ERRNO */
	#define set_errno(err)
#endif /* ERRNO */

#define sock_set_errno(sk, e) do { \
  sk->err = (e); \
  set_errno(sk->err); \
} while (0)

/* Forward delcaration of some functions */
static void event_callback(struct netconn* conn, enum netconn_evt evt, u16_t len);
static void lwip_getsockopt_internal(void* arg);
static void lwip_setsockopt_internal(void* arg);

/**
 * Initialize this module. This function has to be called before any other
 * functions in this module!
 */
void
lwip_socket_init(void)
{
}

/**
 * Map a externally used socket index to the internal socket representation.
 *
 * @param s externally used socket index
 * @return struct lwip_sock for the socket or NULL if not found
 */
static struct lwip_sock*
get_socket(int s)
{
	struct lwip_sock* sock;

	if((s < 0) || (s >= NUM_SOCKETS)) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): invalid\n", s));
		set_errno(EBADF);
		return NULL;
	}

	sock = &sockets[s];

	if(!sock->conn) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): not active\n", s));
		set_errno(EBADF);
		return NULL;
	}

	return sock;
}

/**
 * Same as get_socket but doesn't set errno
 *
 * @param s externally used socket index
 * @return struct lwip_sock for the socket or NULL if not found
 */
static struct lwip_sock*
tryget_socket(int s)
{
	if((s < 0) || (s >= NUM_SOCKETS)) {
		return NULL;
	}

	if(!sockets[s].conn) {
		return NULL;
	}

	return &sockets[s];
}

/**
 * Same as tryget_socket but a global routine.
 *
 * @param s externally used socket index
 * @return struct lwip_sock for the socket or NULL if not found
 */
struct lwip_sock*
lwip_tryget_socket(int s)
{
	return tryget_socket(s);
}

/**
 * Allocate a new socket for a given netconn.
 *
 * @param newconn the netconn for which to allocate a socket
 * @param accepted 1 if socket has been created by accept(),
 *                 0 if socket has been created by socket()
 * @return the index of the new socket; -1 on error
 */
static int
alloc_socket(struct netconn* newconn, int accepted)
{
	int i;
	SYS_ARCH_DECL_PROTECT(lev);

	/* allocate a new socket identifier */
	for(i = 0; i < NUM_SOCKETS; ++i) {
		/* Protect socket array */
		SYS_ARCH_PROTECT(lev);

		if(!sockets[i].conn) {
			sockets[i].conn       = newconn;
			/* The socket is not yet known to anyone, so no need to protect
			   after having marked it as used. */
			SYS_ARCH_UNPROTECT(lev);
			sockets[i].lastdata   = NULL;
			sockets[i].lastoffset = 0;
			sockets[i].rcvevent   = 0;
			/* TCP sendbuf is empty, but the socket is not yet writable until connected
			 * (unless it has been created by accept()). */
			sockets[i].sendevent  = (newconn->type == NETCONN_TCP ? (accepted != 0) : 1);
			sockets[i].errevent   = 0;
			sockets[i].err        = 0;
			sockets[i].select_waiting = 0;
			return i;
		}

		SYS_ARCH_UNPROTECT(lev);
	}

	return -1;
}

/** Free a socket. The socket's netconn must have been
 * delete before!
 *
 * @param sock the socket to free
 * @param is_tcp != 0 for TCP sockets, used to free lastdata
 */
static void
free_socket(struct lwip_sock* sock, int is_tcp)
{
	void* lastdata;
	SYS_ARCH_DECL_PROTECT(lev);

	lastdata         = sock->lastdata;
	sock->lastdata   = NULL;
	sock->lastoffset = 0;
	sock->err        = 0;

	/* Protect socket array */
	SYS_ARCH_PROTECT(lev);
	sock->conn       = NULL;
	SYS_ARCH_UNPROTECT(lev);
	/* don't use 'sock' after this line, as another task might have allocated it */

	if(lastdata != NULL) {
		if(is_tcp) {
			pbuf_free((struct pbuf*)lastdata);
		} else {
			netbuf_delete((struct netbuf*)lastdata);
		}
	}
}

/* Below this, the well-known socket functions are implemented.
 * Use google.com or opengroup.org to get a good description :-)
 *
 * Exceptions are documented!
 */

int
lwip_accept(int s, struct sockaddr* addr, socklen_t* addrlen)
{
	struct lwip_sock* sock, *nsock;
	struct netconn* newconn;
	ip_addr_t naddr;
	u16_t port;
	int newsock;
	struct sockaddr_in sin;
	err_t err;
	SYS_ARCH_DECL_PROTECT(lev);

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d)...\n", s));
	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	if(netconn_is_nonblocking(sock->conn) && (sock->rcvevent <= 0)) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d): returning EWOULDBLOCK\n", s));
		sock_set_errno(sock, EWOULDBLOCK);
		return -1;
	}

	/* wait for a new connection */
	err = netconn_accept(sock->conn, &newconn);

	if(err != ERR_OK) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d): netconn_acept failed, err=%d\n", s, err));

		if(netconn_type(sock->conn) != NETCONN_TCP) {
			sock_set_errno(sock, EOPNOTSUPP);
			return EOPNOTSUPP;
		}

		sock_set_errno(sock, err_to_errno(err));
		return -1;
	}

	LWIP_ASSERT("newconn != NULL", newconn != NULL);
	/* Prevent automatic window updates, we do this on our own! */
	netconn_set_noautorecved(newconn, 1);

	/* get the IP address and port of the remote host */
	err = netconn_peer(newconn, &naddr, &port);

	if(err != ERR_OK) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d): netconn_peer failed, err=%d\n", s, err));
		netconn_delete(newconn);
		sock_set_errno(sock, err_to_errno(err));
		return -1;
	}

	/* Note that POSIX only requires us to check addr is non-NULL. addrlen must
	 * not be NULL if addr is valid.
	 */
	if(NULL != addr) {
		LWIP_ASSERT("addr valid but addrlen NULL", addrlen != NULL);
		memset(&sin, 0, sizeof(sin));
		sin.sin_len = sizeof(sin);
		sin.sin_family = AF_INET;
		sin.sin_port = htons(port);
		inet_addr_from_ipaddr(&sin.sin_addr, &naddr);

		if(*addrlen > sizeof(sin))
			*addrlen = sizeof(sin);

		MEMCPY(addr, &sin, *addrlen);
	}

	newsock = alloc_socket(newconn, 1);

	if(newsock == -1) {
		netconn_delete(newconn);
		sock_set_errno(sock, ENFILE);
		return -1;
	}

	LWIP_ASSERT("invalid socket index", (newsock >= 0) && (newsock < NUM_SOCKETS));
	/* RT-Thread has changed callback when using BSD socket API, so remove this assert. */
	/* LWIP_ASSERT("newconn->callback == event_callback", newconn->callback == event_callback); */
	nsock = &sockets[newsock];

	/* See event_callback: If data comes in right away after an accept, even
	 * though the server task might not have created a new socket yet.
	 * In that case, newconn->socket is counted down (newconn->socket--),
	 * so nsock->rcvevent is >= 1 here!
	 */
	SYS_ARCH_PROTECT(lev);
	nsock->rcvevent += (s16_t)(-1 - newconn->socket);
	newconn->socket = newsock;
	SYS_ARCH_UNPROTECT(lev);

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d) returning new sock=%d addr=", s, newsock));
	ip_addr_debug_print(SOCKETS_DEBUG, &naddr);
	LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F"\n", port));

	sock_set_errno(sock, 0);
	return newsock;
}

int
lwip_bind(int s, const struct sockaddr* name, socklen_t namelen)
{
	struct lwip_sock* sock;
	ip_addr_t local_addr;
	u16_t local_port;
	err_t err;
	const struct sockaddr_in* name_in;

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	/* check size, familiy and alignment of 'name' */
	LWIP_ERROR("lwip_bind: invalid address", ((namelen == sizeof(struct sockaddr_in)) &&
	           ((name->sa_family) == AF_INET) && ((((mem_ptr_t)name) % 4) == 0)),
	           sock_set_errno(sock, err_to_errno(ERR_ARG)); return -1;);
	name_in = (const struct sockaddr_in*)(void*)name;

	inet_addr_to_ipaddr(&local_addr, &name_in->sin_addr);
	local_port = name_in->sin_port;

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d, addr=", s));
	ip_addr_debug_print(SOCKETS_DEBUG, &local_addr);
	LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F")\n", ntohs(local_port)));

	err = netconn_bind(sock->conn, &local_addr, ntohs(local_port));

	if(err != ERR_OK) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d) failed, err=%d\n", s, err));
		sock_set_errno(sock, err_to_errno(err));
		return -1;
	}

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d) succeeded\n", s));
	sock_set_errno(sock, 0);
	return 0;
}

int
lwip_close(int s)
{
	struct lwip_sock* sock;
	int is_tcp = 0;

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_close(%d)\n", s));

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	if(sock->conn != NULL) {
		is_tcp = netconn_type(sock->conn) == NETCONN_TCP;
	} else {
		LWIP_ASSERT("sock->lastdata == NULL", sock->lastdata == NULL);
	}

	netconn_delete(sock->conn);

	free_socket(sock, is_tcp);
	set_errno(0);
	return 0;
}

int
lwip_connect(int s, const struct sockaddr* name, socklen_t namelen)
{
	struct lwip_sock* sock;
	err_t err;
	const struct sockaddr_in* name_in;

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	/* check size, familiy and alignment of 'name' */
	LWIP_ERROR("lwip_connect: invalid address", ((namelen == sizeof(struct sockaddr_in)) &&
	           ((name->sa_family) == AF_INET) && ((((mem_ptr_t)name) % 4) == 0)),
	           sock_set_errno(sock, err_to_errno(ERR_ARG)); return -1;);
	name_in = (const struct sockaddr_in*)(void*)name;

	if(name_in->sin_family == AF_UNSPEC) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d, AF_UNSPEC)\n", s));
		err = netconn_disconnect(sock->conn);
	} else {
		ip_addr_t remote_addr;
		u16_t remote_port;

		inet_addr_to_ipaddr(&remote_addr, &name_in->sin_addr);
		remote_port = name_in->sin_port;

		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d, addr=", s));
		ip_addr_debug_print(SOCKETS_DEBUG, &remote_addr);
		LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F")\n", ntohs(remote_port)));

		err = netconn_connect(sock->conn, &remote_addr, ntohs(remote_port));
	}

	if(err != ERR_OK) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d) failed, err=%d\n", s, err));
		sock_set_errno(sock, err_to_errno(err));
		return -1;
	}

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d) succeeded\n", s));
	sock_set_errno(sock, 0);
	return 0;
}

/**
 * Set a socket into listen mode.
 * The socket may not have been used for another connection previously.
 *
 * @param s the socket to set to listening mode
 * @param backlog (ATTENTION: needs TCP_LISTEN_BACKLOG=1)
 * @return 0 on success, non-zero on failure
 */
int
lwip_listen(int s, int backlog)
{
	struct lwip_sock* sock;
	err_t err;

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_listen(%d, backlog=%d)\n", s, backlog));

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	/* limit the "backlog" parameter to fit in an u8_t */
	backlog = LWIP_MIN(LWIP_MAX(backlog, 0), 0xff);

	err = netconn_listen_with_backlog(sock->conn, (u8_t)backlog);

	if(err != ERR_OK) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_listen(%d) failed, err=%d\n", s, err));

		if(netconn_type(sock->conn) != NETCONN_TCP) {
			sock_set_errno(sock, EOPNOTSUPP);
			return EOPNOTSUPP;
		}

		sock_set_errno(sock, err_to_errno(err));
		return -1;
	}

	sock_set_errno(sock, 0);
	return 0;
}

int
lwip_recvfrom(int s, void* mem, size_t len, int flags,
              struct sockaddr* from, socklen_t* fromlen)
{
	struct lwip_sock* sock;
	void*             buf = NULL;
	struct pbuf*      p;
	u16_t            buflen, copylen;
	int              off = 0;
	ip_addr_t*        addr;
	u16_t            port;
	u8_t             done = 0;
	err_t            err;

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d, %p, %"SZT_F", 0x%x, ..)\n", s, mem, len, flags));
	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	do {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: top while sock->lastdata=%p\n", sock->lastdata));

		/* Check if there is data left from the last recv operation. */
		if(sock->lastdata) {
			buf = sock->lastdata;
		} else {
			/* If this is non-blocking call, then check first */
			if(((flags & MSG_DONTWAIT) || netconn_is_nonblocking(sock->conn)) &&
			        (sock->rcvevent <= 0)) {
				if(off > 0) {
					/* update receive window */
					netconn_recved(sock->conn, (u32_t)off);
					/* already received data, return that */
					sock_set_errno(sock, 0);
					return off;
				}

				LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): returning EWOULDBLOCK\n", s));
				sock_set_errno(sock, EWOULDBLOCK);
				return -1;
			}

			/* No data was left from the previous operation, so we try to get
			   some from the network. */
			if(netconn_type(sock->conn) == NETCONN_TCP) {
				err = netconn_recv_tcp_pbuf(sock->conn, (struct pbuf**)&buf);
			} else {
				err = netconn_recv(sock->conn, (struct netbuf**)&buf);
			}

			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: netconn_recv err=%d, netbuf=%p\n",
			                            err, buf));

			if(err != ERR_OK) {
				if(off > 0) {
					/* update receive window */
					netconn_recved(sock->conn, (u32_t)off);
					/* already received data, return that */
					sock_set_errno(sock, 0);
					return off;
				}

				/* We should really do some error checking here. */
				LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): buf == NULL, error is \"%s\"!\n",
				                            s, lwip_strerr(err)));
				sock_set_errno(sock, err_to_errno(err));

				if(err == ERR_CLSD) {
					return 0;
				} else {
					return -1;
				}
			}

			LWIP_ASSERT("buf != NULL", buf != NULL);
			sock->lastdata = buf;
		}

		if(netconn_type(sock->conn) == NETCONN_TCP) {
			p = (struct pbuf*)buf;
		} else {
			p = ((struct netbuf*)buf)->p;
		}

		buflen = p->tot_len;
		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: buflen=%"U16_F" len=%"SZT_F" off=%d sock->lastoffset=%"U16_F"\n",
		                            buflen, len, off, sock->lastoffset));

		buflen -= sock->lastoffset;

		if(len > buflen) {
			copylen = buflen;
		} else {
			copylen = (u16_t)len;
		}

		/* copy the contents of the received buffer into
		the supplied memory pointer mem */
		pbuf_copy_partial(p, (u8_t*)mem + off, copylen, sock->lastoffset);

		off += copylen;

		if(netconn_type(sock->conn) == NETCONN_TCP) {
			LWIP_ASSERT("invalid copylen, len would underflow", len >= copylen);
			len -= copylen;

			if((len <= 0) ||
			        (p->flags & PBUF_FLAG_PUSH) ||
			        (sock->rcvevent <= 0) ||
			        ((flags & MSG_PEEK) != 0)) {
				done = 1;
			}
		} else {
			done = 1;
		}

		/* Check to see from where the data was.*/
		if(done) {
			ip_addr_t fromaddr;

			if(from && fromlen) {
				struct sockaddr_in sin;

				if(netconn_type(sock->conn) == NETCONN_TCP) {
					addr = &fromaddr;
					netconn_getaddr(sock->conn, addr, &port, 0);
				} else {
					addr = netbuf_fromaddr((struct netbuf*)buf);
					port = netbuf_fromport((struct netbuf*)buf);
				}

				memset(&sin, 0, sizeof(sin));
				sin.sin_len = sizeof(sin);
				sin.sin_family = AF_INET;
				sin.sin_port = htons(port);
				inet_addr_from_ipaddr(&sin.sin_addr, addr);

				if(*fromlen > sizeof(sin)) {
					*fromlen = sizeof(sin);
				}

				MEMCPY(from, &sin, *fromlen);

				LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): addr=", s));
				ip_addr_debug_print(SOCKETS_DEBUG, addr);
				LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F" len=%d\n", port, off));
			} else {
#if SOCKETS_DEBUG

				if(netconn_type(sock->conn) == NETCONN_TCP) {
					addr = &fromaddr;
					netconn_getaddr(sock->conn, addr, &port, 0);
				} else {
					addr = netbuf_fromaddr((struct netbuf*)buf);
					port = netbuf_fromport((struct netbuf*)buf);
				}

				LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): addr=", s));
				ip_addr_debug_print(SOCKETS_DEBUG, addr);
				LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F" len=%d\n", port, off));
#endif /*  SOCKETS_DEBUG */
			}
		}

		/* If we don't peek the incoming message... */
		if((flags & MSG_PEEK) == 0) {
			/* If this is a TCP socket, check if there is data left in the
			   buffer. If so, it should be saved in the sock structure for next
			   time around. */
			if((netconn_type(sock->conn) == NETCONN_TCP) && (buflen - copylen > 0)) {
				sock->lastdata = buf;
				sock->lastoffset += copylen;
				LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: lastdata now netbuf=%p\n", buf));
			} else {
				sock->lastdata = NULL;
				sock->lastoffset = 0;
				LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom: deleting netbuf=%p\n", buf));

				if(netconn_type(sock->conn) == NETCONN_TCP) {
					pbuf_free((struct pbuf*)buf);
				} else {
					netbuf_delete((struct netbuf*)buf);
				}
			}
		}
	} while(!done);

	if(off > 0) {
		/* update receive window */
		netconn_recved(sock->conn, (u32_t)off);
	}

	sock_set_errno(sock, 0);
	return off;
}

int
lwip_read(int s, void* mem, size_t len)
{
	return lwip_recvfrom(s, mem, len, 0, NULL, NULL);
}

int
lwip_recv(int s, void* mem, size_t len, int flags)
{
	return lwip_recvfrom(s, mem, len, flags, NULL, NULL);
}

int
lwip_send(int s, const void* data, size_t size, int flags)
{
	struct lwip_sock* sock;
	err_t err;
	u8_t write_flags;
	size_t written;

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d, data=%p, size=%"SZT_F", flags=0x%x)\n",
	                            s, data, size, flags));

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	if(sock->conn->type != NETCONN_TCP) {
#if (LWIP_UDP || LWIP_RAW)
		return lwip_sendto(s, data, size, flags, NULL, 0);
#else /* (LWIP_UDP || LWIP_RAW) */
		sock_set_errno(sock, err_to_errno(ERR_ARG));
		return -1;
#endif /* (LWIP_UDP || LWIP_RAW) */
	}

	write_flags = NETCONN_COPY |
	              ((flags & MSG_MORE)     ? NETCONN_MORE      : 0) |
	              ((flags & MSG_DONTWAIT) ? NETCONN_DONTBLOCK : 0);
	written = 0;
	err = netconn_write_partly(sock->conn, data, size, write_flags, &written);

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d) err=%d written=%"SZT_F"\n", s, err, written));
	sock_set_errno(sock, err_to_errno(err));
	return (err == ERR_OK ? (int)written : -1);
}

int
lwip_sendto(int s, const void* data, size_t size, int flags,
            const struct sockaddr* to, socklen_t tolen)
{
	struct lwip_sock* sock;
	err_t err;
	u16_t short_size;
	const struct sockaddr_in* to_in;
	u16_t remote_port;
#if !LWIP_TCPIP_CORE_LOCKING
	struct netbuf buf;
#endif

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	if(sock->conn->type == NETCONN_TCP) {
#if LWIP_TCP
		return lwip_send(s, data, size, flags);
#else /* LWIP_TCP */
		LWIP_UNUSED_ARG(flags);
		sock_set_errno(sock, err_to_errno(ERR_ARG));
		return -1;
#endif /* LWIP_TCP */
	}

	/* @todo: split into multiple sendto's? */
	LWIP_ASSERT("lwip_sendto: size must fit in u16_t", size <= 0xffff);
	short_size = (u16_t)size;
	LWIP_ERROR("lwip_sendto: invalid address", (((to == NULL) && (tolen == 0)) ||
	           ((tolen == sizeof(struct sockaddr_in)) &&
	            ((to->sa_family) == AF_INET) && ((((mem_ptr_t)to) % 4) == 0))),
	           sock_set_errno(sock, err_to_errno(ERR_ARG)); return -1;);
	to_in = (const struct sockaddr_in*)(void*)to;

#if LWIP_TCPIP_CORE_LOCKING
	/* Should only be consider like a sample or a simple way to experiment this option (no check of "to" field...) */
	{
		struct pbuf* p;
		ip_addr_t* remote_addr;

#if LWIP_NETIF_TX_SINGLE_PBUF
		p = pbuf_alloc(PBUF_TRANSPORT, short_size, PBUF_RAM);

		if(p != NULL) {
#if LWIP_CHECKSUM_ON_COPY
			u16_t chksum = 0;

			if(sock->conn->type != NETCONN_RAW) {
				chksum = LWIP_CHKSUM_COPY(p->payload, data, short_size);
			} else
#endif /* LWIP_CHECKSUM_ON_COPY */
				MEMCPY(p->payload, data, size);

#else /* LWIP_NETIF_TX_SINGLE_PBUF */
		p = pbuf_alloc(PBUF_TRANSPORT, short_size, PBUF_REF);

		if(p != NULL) {
			p->payload = (void*)data;
#endif /* LWIP_NETIF_TX_SINGLE_PBUF */

			if(to_in != NULL) {
				inet_addr_to_ipaddr_p(remote_addr, &to_in->sin_addr);
				remote_port = ntohs(to_in->sin_port);
			} else {
				remote_addr = &sock->conn->pcb.ip->remote_ip;
#if LWIP_UDP

				if(NETCONNTYPE_GROUP(sock->conn->type) == NETCONN_UDP) {
					remote_port = sock->conn->pcb.udp->remote_port;
				} else
#endif /* LWIP_UDP */
				{
					remote_port = 0;
				}
			}

			LOCK_TCPIP_CORE();

			if(netconn_type(sock->conn) == NETCONN_RAW) {
#if LWIP_RAW
				err = sock->conn->last_err = raw_sendto(sock->conn->pcb.raw, p, remote_addr);
#else /* LWIP_RAW */
				err = ERR_ARG;
#endif /* LWIP_RAW */
			}

#if LWIP_UDP && LWIP_RAW
			else
#endif /* LWIP_UDP && LWIP_RAW */
			{
#if LWIP_UDP
#if LWIP_CHECKSUM_ON_COPY && LWIP_NETIF_TX_SINGLE_PBUF
				err = sock->conn->last_err = udp_sendto_chksum(sock->conn->pcb.udp, p,
				                             remote_addr, remote_port, 1, chksum);
#else /* LWIP_CHECKSUM_ON_COPY && LWIP_NETIF_TX_SINGLE_PBUF */
				err = sock->conn->last_err = udp_sendto(sock->conn->pcb.udp, p,
				                                        remote_addr, remote_port);
#endif /* LWIP_CHECKSUM_ON_COPY && LWIP_NETIF_TX_SINGLE_PBUF */
#else /* LWIP_UDP */
				err = ERR_ARG;
#endif /* LWIP_UDP */
			}

			UNLOCK_TCPIP_CORE();

			pbuf_free(p);
		} else {
			err = ERR_MEM;
		}
	}

#else /* LWIP_TCPIP_CORE_LOCKING */
	/* initialize a buffer */
	buf.p = buf.ptr = NULL;
#if LWIP_CHECKSUM_ON_COPY
	buf.flags = 0;
#endif /* LWIP_CHECKSUM_ON_COPY */

	if(to) {
		inet_addr_to_ipaddr(&buf.addr, &to_in->sin_addr);
		remote_port           = ntohs(to_in->sin_port);
		netbuf_fromport(&buf) = remote_port;
	} else {
		remote_port           = 0;
		ip_addr_set_any(&buf.addr);
		netbuf_fromport(&buf) = 0;
	}

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_sendto(%d, data=%p, short_size=%"U16_F", flags=0x%x to=",
	                            s, data, short_size, flags));
	ip_addr_debug_print(SOCKETS_DEBUG, &buf.addr);
	LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F"\n", remote_port));

	/* make the buffer point to the data that should be sent */
#if LWIP_NETIF_TX_SINGLE_PBUF

	/* Allocate a new netbuf and copy the data into it. */
	if(netbuf_alloc(&buf, short_size) == NULL) {
		err = ERR_MEM;
	} else {
#if LWIP_CHECKSUM_ON_COPY

		if(sock->conn->type != NETCONN_RAW) {
			u16_t chksum = LWIP_CHKSUM_COPY(buf.p->payload, data, short_size);
			netbuf_set_chksum(&buf, chksum);
			err = ERR_OK;
		} else
#endif /* LWIP_CHECKSUM_ON_COPY */
		{
			err = netbuf_take(&buf, data, short_size);
		}
	}

#else /* LWIP_NETIF_TX_SINGLE_PBUF */
	err = netbuf_ref(&buf, data, short_size);
#endif /* LWIP_NETIF_TX_SINGLE_PBUF */

	if(err == ERR_OK) {
		/* send the data */
		err = netconn_send(sock->conn, &buf);
	}

	/* deallocated the buffer */
	netbuf_free(&buf);
#endif /* LWIP_TCPIP_CORE_LOCKING */
	sock_set_errno(sock, err_to_errno(err));
	return (err == ERR_OK ? short_size : -1);
}

int
lwip_socket(int domain, int type, int protocol) {
	struct netconn* conn;
	int i;

	LWIP_UNUSED_ARG(domain);

	/* create a netconn */
	switch(type) {
		case SOCK_RAW:
			conn = netconn_new_with_proto_and_callback(NETCONN_RAW, (u8_t)protocol, event_callback);
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_RAW, %d) = ",
			                            domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));
			break;

		case SOCK_DGRAM:
			conn = netconn_new_with_callback((protocol == IPPROTO_UDPLITE) ?
			                                 NETCONN_UDPLITE : NETCONN_UDP, event_callback);
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_DGRAM, %d) = ",
			                            domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));
			break;

		case SOCK_STREAM:
			conn = netconn_new_with_callback(NETCONN_TCP, event_callback);
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_STREAM, %d) = ",
			                            domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));

			if(conn != NULL) {
				/* Prevent automatic window updates, we do this on our own! */
				netconn_set_noautorecved(conn, 1);
			}

			break;

		default:
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%d, %d/UNKNOWN, %d) = -1\n",
			                            domain, type, protocol));
			set_errno(EINVAL);
			return -1;
	}

	if(!conn) {
		LWIP_DEBUGF(SOCKETS_DEBUG, ("-1 / ENOBUFS (could not create netconn)\n"));
		set_errno(ENOBUFS);
		return -1;
	}

	i = alloc_socket(conn, 0);

	if(i == -1) {
		netconn_delete(conn);
		set_errno(ENFILE);
		return -1;
	}

	conn->socket = i;
	LWIP_DEBUGF(SOCKETS_DEBUG, ("%d\n", i));
	set_errno(0);
	return i;
}

int
lwip_write(int s, const void* data, size_t size) {
	return lwip_send(s, data, size, 0);
}

/**
 * Go through the readset and writeset lists and see which socket of the sockets
 * set in the sets has events. On return, readset, writeset and exceptset have
 * the sockets enabled that had events.
 *
 * exceptset is not used for now!!!
 *
 * @param maxfdp1 the highest socket index in the sets
 * @param readset_in:    set of sockets to check for read events
 * @param writeset_in:   set of sockets to check for write events
 * @param exceptset_in:  set of sockets to check for error events
 * @param readset_out:   set of sockets that had read events
 * @param writeset_out:  set of sockets that had write events
 * @param exceptset_out: set os sockets that had error events
 * @return number of sockets that had events (read/write/exception) (>= 0)
 */
static int
lwip_selscan(int maxfdp1, fd_set * readset_in, fd_set * writeset_in, fd_set * exceptset_in,
             fd_set * readset_out, fd_set * writeset_out, fd_set * exceptset_out) {
	int i, nready = 0;
	fd_set lreadset, lwriteset, lexceptset;
	struct lwip_sock* sock;
	SYS_ARCH_DECL_PROTECT(lev);

	FD_ZERO(&lreadset);
	FD_ZERO(&lwriteset);
	FD_ZERO(&lexceptset);

	/* Go through each socket in each list to count number of sockets which
	   currently match */
	for(i = 0; i < maxfdp1; i++) {
		void* lastdata = NULL;
		s16_t rcvevent = 0;
		u16_t sendevent = 0;
		u16_t errevent = 0;
		/* First get the socket's status (protected)... */
		SYS_ARCH_PROTECT(lev);
		sock = tryget_socket(i);

		if(sock != NULL) {
			lastdata = sock->lastdata;
			rcvevent = sock->rcvevent;
			sendevent = sock->sendevent;
			errevent = sock->errevent;
		}

		SYS_ARCH_UNPROTECT(lev);

		/* ... then examine it: */
		/* See if netconn of this socket is ready for read */
		if(readset_in && FD_ISSET(i, readset_in) && ((lastdata != NULL) || (rcvevent > 0))) {
			FD_SET(i, &lreadset);
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_selscan: fd=%d ready for reading\n", i));
			nready++;
		}

		/* See if netconn of this socket is ready for write */
		if(writeset_in && FD_ISSET(i, writeset_in) && (sendevent != 0)) {
			FD_SET(i, &lwriteset);
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_selscan: fd=%d ready for writing\n", i));
			nready++;
		}

		/* See if netconn of this socket had an error */
		if(exceptset_in && FD_ISSET(i, exceptset_in) && (errevent != 0)) {
			FD_SET(i, &lexceptset);
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_selscan: fd=%d ready for exception\n", i));
			nready++;
		}
	}

	/* copy local sets to the ones provided as arguments */
	*readset_out = lreadset;
	*writeset_out = lwriteset;
	*exceptset_out = lexceptset;

	LWIP_ASSERT("nready >= 0", nready >= 0);
	return nready;
}

/**
 * Processing exceptset is not yet implemented.
 */
int
lwip_select(int maxfdp1, fd_set * readset, fd_set * writeset, fd_set * exceptset,
            struct timeval * timeout) {
	u32_t waitres = 0;
	int nready;
	fd_set lreadset, lwriteset, lexceptset;
	u32_t msectimeout;
	struct lwip_select_cb select_cb;
	err_t err;
	int i;
	SYS_ARCH_DECL_PROTECT(lev);

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select(%d, %p, %p, %p, tvsec=%"S32_F" tvusec=%"S32_F")\n",
	                            maxfdp1, (void*)readset, (void*) writeset, (void*) exceptset,
	                            timeout ? (s32_t)timeout->tv_sec : (s32_t) -1,
	                            timeout ? (s32_t)timeout->tv_usec : (s32_t) -1));

	/* Go through each socket in each list to count number of sockets which
	   currently match */
	nready = lwip_selscan(maxfdp1, readset, writeset, exceptset, &lreadset, &lwriteset, &lexceptset);

	/* If we don't have any current events, then suspend if we are supposed to */
	if(!nready) {
		if(timeout && timeout->tv_sec == 0 && timeout->tv_usec == 0) {
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: no timeout, returning 0\n"));
			/* This is OK as the local fdsets are empty and nready is zero,
			   or we would have returned earlier. */
			goto return_copy_fdsets;
		}

		/* None ready: add our semaphore to list:
		   We don't actually need any dynamic memory. Our entry on the
		   list is only valid while we are in this function, so it's ok
		   to use local variables. */

		select_cb.next = NULL;
		select_cb.prev = NULL;
		select_cb.readset = readset;
		select_cb.writeset = writeset;
		select_cb.exceptset = exceptset;
		select_cb.sem_signalled = 0;
		err = sys_sem_new(&select_cb.sem, 0);

		if(err != ERR_OK) {
			/* failed to create semaphore */
			set_errno(ENOMEM);
			return -1;
		}

		/* Protect the select_cb_list */
		SYS_ARCH_PROTECT(lev);

		/* Put this select_cb on top of list */
		select_cb.next = select_cb_list;

		if(select_cb_list != NULL) {
			select_cb_list->prev = &select_cb;
		}

		select_cb_list = &select_cb;
		/* Increasing this counter tells even_callback that the list has changed. */
		select_cb_ctr++;

		/* Now we can safely unprotect */
		SYS_ARCH_UNPROTECT(lev);

		/* Increase select_waiting for each socket we are interested in */
		for(i = 0; i < maxfdp1; i++) {
			if((readset && FD_ISSET(i, readset)) ||
			        (writeset && FD_ISSET(i, writeset)) ||
			        (exceptset && FD_ISSET(i, exceptset))) {
				struct lwip_sock* sock = tryget_socket(i);
				LWIP_ASSERT("sock != NULL", sock != NULL);
				SYS_ARCH_PROTECT(lev);
				sock->select_waiting++;
				LWIP_ASSERT("sock->select_waiting > 0", sock->select_waiting > 0);
				SYS_ARCH_UNPROTECT(lev);
			}
		}

		/* Call lwip_selscan again: there could have been events between
		   the last scan (whithout us on the list) and putting us on the list! */
		nready = lwip_selscan(maxfdp1, readset, writeset, exceptset, &lreadset, &lwriteset, &lexceptset);

		if(!nready) {
			/* Still none ready, just wait to be woken */
			if(timeout == 0) {
				/* Wait forever */
				msectimeout = 0;
			} else {
				msectimeout = ((timeout->tv_sec * 1000) + ((timeout->tv_usec + 500) / 1000));

				if(msectimeout == 0) {
					/* Wait 1ms at least (0 means wait forever) */
					msectimeout = 1;
				}
			}

			waitres = sys_arch_sem_wait(&select_cb.sem, msectimeout);
		}

		/* Increase select_waiting for each socket we are interested in */
		for(i = 0; i < maxfdp1; i++) {
			if((readset && FD_ISSET(i, readset)) ||
			        (writeset && FD_ISSET(i, writeset)) ||
			        (exceptset && FD_ISSET(i, exceptset))) {
				struct lwip_sock* sock = tryget_socket(i);
				LWIP_ASSERT("sock != NULL", sock != NULL);
				SYS_ARCH_PROTECT(lev);
				sock->select_waiting--;
				LWIP_ASSERT("sock->select_waiting >= 0", sock->select_waiting >= 0);
				SYS_ARCH_UNPROTECT(lev);
			}
		}

		/* Take us off the list */
		SYS_ARCH_PROTECT(lev);

		if(select_cb.next != NULL) {
			select_cb.next->prev = select_cb.prev;
		}

		if(select_cb_list == &select_cb) {
			LWIP_ASSERT("select_cb.prev == NULL", select_cb.prev == NULL);
			select_cb_list = select_cb.next;
		} else {
			LWIP_ASSERT("select_cb.prev != NULL", select_cb.prev != NULL);
			select_cb.prev->next = select_cb.next;
		}

		/* Increasing this counter tells even_callback that the list has changed. */
		select_cb_ctr++;
		SYS_ARCH_UNPROTECT(lev);

		sys_sem_free(&select_cb.sem);

		if(waitres == SYS_ARCH_TIMEOUT)  {
			/* Timeout */
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: timeout expired\n"));
			/* This is OK as the local fdsets are empty and nready is zero,
			   or we would have returned earlier. */
			goto return_copy_fdsets;
		}

		/* See what's set */
		nready = lwip_selscan(maxfdp1, readset, writeset, exceptset, &lreadset, &lwriteset, &lexceptset);
	}

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: nready=%d\n", nready));
return_copy_fdsets:
	set_errno(0);

	if(readset) {
		*readset = lreadset;
	}

	if(writeset) {
		*writeset = lwriteset;
	}

	if(exceptset) {
		*exceptset = lexceptset;
	}


	return nready;
}

/**
 * Callback registered in the netconn layer for each socket-netconn.
 * Processes recvevent (data available) and wakes up tasks waiting for select.
 */
static void
event_callback(struct netconn * conn, enum netconn_evt evt, u16_t len) {
	int s;
	struct lwip_sock* sock;
	struct lwip_select_cb* scb;
	int last_select_cb_ctr;
	SYS_ARCH_DECL_PROTECT(lev);

	LWIP_UNUSED_ARG(len);

	/* Get socket */
	if(conn) {
		s = conn->socket;

		if(s < 0) {
			/* Data comes in right away after an accept, even though
			 * the server task might not have created a new socket yet.
			 * Just count down (or up) if that's the case and we
			 * will use the data later. Note that only receive events
			 * can happen before the new socket is set up. */
			SYS_ARCH_PROTECT(lev);

			if(conn->socket < 0) {
				if(evt == NETCONN_EVT_RCVPLUS) {
					conn->socket--;
				}

				SYS_ARCH_UNPROTECT(lev);
				return;
			}

			s = conn->socket;
			SYS_ARCH_UNPROTECT(lev);
		}

		sock = get_socket(s);

		if(!sock) {
			return;
		}
	} else {
		return;
	}

	SYS_ARCH_PROTECT(lev);

	/* Set event as required */
	switch(evt) {
		case NETCONN_EVT_RCVPLUS:
			sock->rcvevent++;
			break;

		case NETCONN_EVT_RCVMINUS:
			sock->rcvevent--;
			break;

		case NETCONN_EVT_SENDPLUS:
			sock->sendevent = 1;
			break;

		case NETCONN_EVT_SENDMINUS:
			sock->sendevent = 0;
			break;

		case NETCONN_EVT_ERROR:
			sock->errevent = 1;
			break;

		default:
			LWIP_ASSERT("unknown event", 0);
			break;
	}

	if(sock->select_waiting == 0) {
		/* noone is waiting for this socket, no need to check select_cb_list */
		SYS_ARCH_UNPROTECT(lev);
		return;
	}

	/* Now decide if anyone is waiting for this socket */
	/* NOTE: This code goes through the select_cb_list list multiple times
	   ONLY IF a select was actually waiting. We go through the list the number
	   of waiting select calls + 1. This list is expected to be small. */

	/* At this point, SYS_ARCH is still protected! */
again:

	for(scb = select_cb_list; scb != NULL; scb = scb->next) {
		if(scb->sem_signalled == 0) {
			/* semaphore not signalled yet */
			int do_signal = 0;

			/* Test this select call for our socket */
			if(sock->rcvevent > 0) {
				if(scb->readset && FD_ISSET(s, scb->readset)) {
					do_signal = 1;
				}
			}

			if(sock->sendevent != 0) {
				if(!do_signal && scb->writeset && FD_ISSET(s, scb->writeset)) {
					do_signal = 1;
				}
			}

			if(sock->errevent != 0) {
				if(!do_signal && scb->exceptset && FD_ISSET(s, scb->exceptset)) {
					do_signal = 1;
				}
			}

			if(do_signal) {
				scb->sem_signalled = 1;
				/* Don't call SYS_ARCH_UNPROTECT() before signaling the semaphore, as this might
				   lead to the select thread taking itself off the list, invalidagin the semaphore. */
				sys_sem_signal(&scb->sem);
			}
		}

		/* unlock interrupts with each step */
		last_select_cb_ctr = select_cb_ctr;
		SYS_ARCH_UNPROTECT(lev);
		/* this makes sure interrupt protection time is short */
		SYS_ARCH_PROTECT(lev);

		if(last_select_cb_ctr != select_cb_ctr) {
			/* someone has changed select_cb_list, restart at the beginning */
			goto again;
		}
	}

	SYS_ARCH_UNPROTECT(lev);
}

/**
 * Unimplemented: Close one end of a full-duplex connection.
 * Currently, the full connection is closed.
 */
int
lwip_shutdown(int s, int how) {
	struct lwip_sock* sock;
	err_t err;
	u8_t shut_rx = 0, shut_tx = 0;

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_shutdown(%d, how=%d)\n", s, how));

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	if(sock->conn != NULL) {
		if(netconn_type(sock->conn) != NETCONN_TCP) {
			sock_set_errno(sock, EOPNOTSUPP);
			return EOPNOTSUPP;
		}
	} else {
		sock_set_errno(sock, ENOTCONN);
		return ENOTCONN;
	}

	if(how == SHUT_RD) {
		shut_rx = 1;
	} else if(how == SHUT_WR) {
		shut_tx = 1;
	} else if(how == SHUT_RDWR) {
		shut_rx = 1;
		shut_tx = 1;
	} else {
		sock_set_errno(sock, EINVAL);
		return EINVAL;
	}

	err = netconn_shutdown(sock->conn, shut_rx, shut_tx);

	sock_set_errno(sock, err_to_errno(err));
	return (err == ERR_OK ? 0 : -1);
}

static int
lwip_getaddrname(int s, struct sockaddr * name, socklen_t* namelen, u8_t local) {
	struct lwip_sock* sock;
	struct sockaddr_in sin;
	ip_addr_t naddr;

	sock = get_socket(s);

	if(!sock) {
		return -1;
	}

	memset(&sin, 0, sizeof(sin));
	sin.sin_len = sizeof(sin);
	sin.sin_family = AF_INET;

	/* get the IP address and port */
	netconn_getaddr(sock->conn, &naddr, &sin.sin_port, local);

	LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getaddrname(%d, addr=", s));
	ip_addr_debug_print(SOCKETS_DEBUG, &naddr);
	LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F")\n", sin.sin_port));

	sin.sin_port = htons(sin.sin_port);
	inet_addr_from_ipaddr(&sin.sin_addr, &naddr);

	if(*namelen > sizeof(sin)) {
		*namelen = sizeof(sin);
	}

	MEMCPY(name, &sin, *namelen);
	sock_set_errno(sock, 0);
	return 0;
}

int
lwip_getpeername(int s, struct sockaddr * name, socklen_t* namelen) {
	return lwip_getaddrname(s, name, namelen, 0);
}

int
lwip_getsockname(int s, struct sockaddr * name, socklen_t* namelen) {
	return lwip_getaddrname(s, name, namelen, 1);
}

int
lwip_getsockopt(int s, int level, int optname, void* optval, socklen_t* optlen) {
	err_t err = ERR_OK;
	struct lwip_sock* sock = get_socket(s);
	struct lwip_setgetsockopt_data data;

	if(!sock) {
		return -1;
	}

	if((NULL == optval) || (NULL == optlen)) {
		sock_set_errno(sock, EFAULT);
		return -1;
	}

	/* Do length and type checks for the various options first, to keep it readable. */
	switch(level) {

		/* Level: SOL_SOCKET */
		case SOL_SOCKET:
			switch(optname) {

				case SO_ACCEPTCONN:
				case SO_BROADCAST:

				/* UNIMPL case SO_DEBUG: */
				/* UNIMPL case SO_DONTROUTE: */
				case SO_ERROR:
				case SO_KEEPALIVE:
					/* UNIMPL case SO_CONTIMEO: */
#if LWIP_SO_SNDTIMEO
				case SO_SNDTIMEO:
#endif /* LWIP_SO_SNDTIMEO */
#if LWIP_SO_RCVTIMEO
				case SO_RCVTIMEO:
#endif /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
				case SO_RCVBUF:
#endif /* LWIP_SO_RCVBUF */
					/* UNIMPL case SO_OOBINLINE: */
					/* UNIMPL case SO_SNDBUF: */
					/* UNIMPL case SO_RCVLOWAT: */
					/* UNIMPL case SO_SNDLOWAT: */
#if SO_REUSE
				case SO_REUSEADDR:
				case SO_REUSEPORT:
#endif /* SO_REUSE */
				case SO_TYPE:

					/* UNIMPL case SO_USELOOPBACK: */
					if(*optlen < sizeof(int)) {
						err = EINVAL;
					}

					break;

				case SO_NO_CHECK:
					if(*optlen < sizeof(int)) {
						err = EINVAL;
					}

#if LWIP_UDP

					if((sock->conn->type != NETCONN_UDP) ||
					        ((udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_UDPLITE) != 0)) {
						/* this flag is only available for UDP, not for UDP lite */
						err = EAFNOSUPPORT;
					}

#endif /* LWIP_UDP */
					break;

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;

		/* Level: IPPROTO_IP */
		case IPPROTO_IP:
			switch(optname) {
				/* UNIMPL case IP_HDRINCL: */
				/* UNIMPL case IP_RCVDSTADDR: */
				/* UNIMPL case IP_RCVIF: */
				case IP_TTL:
				case IP_TOS:
					if(*optlen < sizeof(int)) {
						err = EINVAL;
					}

					break;
#if LWIP_IGMP

				case IP_MULTICAST_TTL:
					if(*optlen < sizeof(u8_t)) {
						err = EINVAL;
					}

					break;

				case IP_MULTICAST_IF:
					if(*optlen < sizeof(struct in_addr)) {
						err = EINVAL;
					}

					break;

				case IP_MULTICAST_LOOP:
					if(*optlen < sizeof(u8_t)) {
						err = EINVAL;
					}

					if(NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
						err = EAFNOSUPPORT;
					}

					break;
#endif /* LWIP_IGMP */

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;

#if LWIP_TCP

		/* Level: IPPROTO_TCP */
		case IPPROTO_TCP:
			if(*optlen < sizeof(int)) {
				err = EINVAL;
				break;
			}

			/* If this is no TCP socket, ignore any options. */
			if(sock->conn->type != NETCONN_TCP)
				return 0;

			switch(optname) {
				case TCP_NODELAY:
				case TCP_KEEPALIVE:
#if LWIP_TCP_KEEPALIVE
				case TCP_KEEPIDLE:
				case TCP_KEEPINTVL:
				case TCP_KEEPCNT:
#endif /* LWIP_TCP_KEEPALIVE */
					break;

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_TCP, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;
#endif /* LWIP_TCP */
#if LWIP_UDP && LWIP_UDPLITE

		/* Level: IPPROTO_UDPLITE */
		case IPPROTO_UDPLITE:
			if(*optlen < sizeof(int)) {
				err = EINVAL;
				break;
			}

			/* If this is no UDP lite socket, ignore any options. */
			if(sock->conn->type != NETCONN_UDPLITE) {
				return 0;
			}

			switch(optname) {
				case UDPLITE_SEND_CSCOV:
				case UDPLITE_RECV_CSCOV:
					break;

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_UDPLITE, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;
#endif /* LWIP_UDP && LWIP_UDPLITE*/

		/* UNDEFINED LEVEL */
		default:
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, level=0x%x, UNIMPL: optname=0x%x, ..)\n",
			                            s, level, optname));
			err = ENOPROTOOPT;
	}  /* switch */


	if(err != ERR_OK) {
		sock_set_errno(sock, err);
		return -1;
	}

	/* Now do the actual option processing */
	data.sock = sock;
#ifdef LWIP_DEBUG
	data.s = s;
#endif /* LWIP_DEBUG */
	data.level = level;
	data.optname = optname;
	data.optval = optval;
	data.optlen = optlen;
	data.err = err;
	tcpip_callback(lwip_getsockopt_internal, &data);
	sys_arch_sem_wait(&sock->conn->op_completed, 0);
	/* maybe lwip_getsockopt_internal has changed err */
	err = data.err;

	sock_set_errno(sock, err);
	return err ? -1 : 0;
}

static void
lwip_getsockopt_internal(void* arg) {
	struct lwip_sock* sock;
#ifdef LWIP_DEBUG
	int s;
#endif /* LWIP_DEBUG */
	int level, optname;
	void* optval;
	struct lwip_setgetsockopt_data* data;

	LWIP_ASSERT("arg != NULL", arg != NULL);

	data = (struct lwip_setgetsockopt_data*)arg;
	sock = data->sock;
#ifdef LWIP_DEBUG
	s = data->s;
#endif /* LWIP_DEBUG */
	level = data->level;
	optname = data->optname;
	optval = data->optval;

	switch(level) {

		/* Level: SOL_SOCKET */
		case SOL_SOCKET:
			switch(optname) {

				/* The option flags */
				case SO_ACCEPTCONN:
				case SO_BROADCAST:

				/* UNIMPL case SO_DEBUG: */
				/* UNIMPL case SO_DONTROUTE: */
				case SO_KEEPALIVE:
					/* UNIMPL case SO_OOBINCLUDE: */
#if SO_REUSE
				case SO_REUSEADDR:
				case SO_REUSEPORT:
#endif /* SO_REUSE */
					/*case SO_USELOOPBACK: UNIMPL */
					*(int*)optval = ip_get_option(sock->conn->pcb.ip, optname);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, optname=0x%x, ..) = %s\n",
					                            s, optname, (*(int*)optval ? "on" : "off")));
					break;

				case SO_TYPE:
					switch(NETCONNTYPE_GROUP(sock->conn->type)) {
						case NETCONN_RAW:
							*(int*)optval = SOCK_RAW;
							break;

						case NETCONN_TCP:
							*(int*)optval = SOCK_STREAM;
							break;

						case NETCONN_UDP:
							*(int*)optval = SOCK_DGRAM;
							break;

						default: /* unrecognized socket type */
							*(int*)optval = sock->conn->type;
							LWIP_DEBUGF(SOCKETS_DEBUG,
							            ("lwip_getsockopt(%d, SOL_SOCKET, SO_TYPE): unrecognized socket type %d\n",
							             s, *(int*)optval));
					}  /* switch (sock->conn->type) */

					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, SO_TYPE) = %d\n",
					                            s, *(int*)optval));
					break;

				case SO_ERROR:

					/* only overwrite ERR_OK or tempoary errors */
					if((sock->err == 0) || (sock->err == EINPROGRESS)) {
						sock_set_errno(sock, err_to_errno(sock->conn->last_err));
					}

					*(int*)optval = sock->err;
					sock->err = 0;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, SO_ERROR) = %d\n",
					                            s, *(int*)optval));
					break;

#if LWIP_SO_SNDTIMEO

				case SO_SNDTIMEO:
					*(int*)optval = netconn_get_sendtimeout(sock->conn);
					break;
#endif /* LWIP_SO_SNDTIMEO */
#if LWIP_SO_RCVTIMEO

				case SO_RCVTIMEO:
					*(int*)optval = netconn_get_recvtimeout(sock->conn);
					break;
#endif /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF

				case SO_RCVBUF:
					*(int*)optval = netconn_get_recvbufsize(sock->conn);
					break;
#endif /* LWIP_SO_RCVBUF */
#if LWIP_UDP

				case SO_NO_CHECK:
					*(int*)optval = (udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_NOCHKSUM) ? 1 : 0;
					break;
#endif /* LWIP_UDP*/

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;

		/* Level: IPPROTO_IP */
		case IPPROTO_IP:
			switch(optname) {
				case IP_TTL:
					*(int*)optval = sock->conn->pcb.ip->ttl;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_TTL) = %d\n",
					                            s, *(int*)optval));
					break;

				case IP_TOS:
					*(int*)optval = sock->conn->pcb.ip->tos;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_TOS) = %d\n",
					                            s, *(int*)optval));
					break;
#if LWIP_IGMP

				case IP_MULTICAST_TTL:
					*(u8_t*)optval = sock->conn->pcb.ip->ttl;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_MULTICAST_TTL) = %d\n",
					                            s, *(int*)optval));
					break;

				case IP_MULTICAST_IF:
					inet_addr_from_ipaddr((struct in_addr*)optval, &sock->conn->pcb.udp->multicast_ip);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_MULTICAST_IF) = 0x%"X32_F"\n",
					                            s, *(u32_t*)optval));
					break;

				case IP_MULTICAST_LOOP:
					if((sock->conn->pcb.udp->flags & UDP_FLAGS_MULTICAST_LOOP) != 0) {
						*(u8_t*)optval = 1;
					} else {
						*(u8_t*)optval = 0;
					}

					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_MULTICAST_LOOP) = %d\n",
					                            s, *(int*)optval));
					break;
#endif /* LWIP_IGMP */

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;

#if LWIP_TCP

		/* Level: IPPROTO_TCP */
		case IPPROTO_TCP:
			switch(optname) {
				case TCP_NODELAY:
					*(int*)optval = tcp_nagle_disabled(sock->conn->pcb.tcp);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_TCP, TCP_NODELAY) = %s\n",
					                            s, (*(int*)optval) ? "on" : "off"));
					break;

				case TCP_KEEPALIVE:
					*(int*)optval = (int)sock->conn->pcb.tcp->keep_idle;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPALIVE) = %d\n",
					                            s, *(int*)optval));
					break;

#if LWIP_TCP_KEEPALIVE

				case TCP_KEEPIDLE:
					*(int*)optval = (int)(sock->conn->pcb.tcp->keep_idle / 1000);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPIDLE) = %d\n",
					                            s, *(int*)optval));
					break;

				case TCP_KEEPINTVL:
					*(int*)optval = (int)(sock->conn->pcb.tcp->keep_intvl / 1000);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPINTVL) = %d\n",
					                            s, *(int*)optval));
					break;

				case TCP_KEEPCNT:
					*(int*)optval = (int)sock->conn->pcb.tcp->keep_cnt;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, TCP_KEEPCNT) = %d\n",
					                            s, *(int*)optval));
					break;
#endif /* LWIP_TCP_KEEPALIVE */

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;
#endif /* LWIP_TCP */
#if LWIP_UDP && LWIP_UDPLITE

		/* Level: IPPROTO_UDPLITE */
		case IPPROTO_UDPLITE:
			switch(optname) {
				case UDPLITE_SEND_CSCOV:
					*(int*)optval = sock->conn->pcb.udp->chksum_len_tx;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_UDPLITE, UDPLITE_SEND_CSCOV) = %d\n",
					                            s, (*(int*)optval)));
					break;

				case UDPLITE_RECV_CSCOV:
					*(int*)optval = sock->conn->pcb.udp->chksum_len_rx;
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_UDPLITE, UDPLITE_RECV_CSCOV) = %d\n",
					                            s, (*(int*)optval)));
					break;

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;
#endif /* LWIP_UDP */

		default:
			LWIP_ASSERT("unhandled level", 0);
			break;
	} /* switch (level) */

	sys_sem_signal(&sock->conn->op_completed);
}

int
lwip_setsockopt(int s, int level, int optname, const void* optval, socklen_t optlen) {
	struct lwip_sock* sock = get_socket(s);
	err_t err = ERR_OK;
	struct lwip_setgetsockopt_data data;

	if(!sock) {
		return -1;
	}

	if(NULL == optval) {
		sock_set_errno(sock, EFAULT);
		return -1;
	}

	/* Do length and type checks for the various options first, to keep it readable. */
	switch(level) {

		/* Level: SOL_SOCKET */
		case SOL_SOCKET:
			switch(optname) {

				case SO_BROADCAST:

				/* UNIMPL case SO_DEBUG: */
				/* UNIMPL case SO_DONTROUTE: */
				case SO_KEEPALIVE:
					/* UNIMPL case case SO_CONTIMEO: */
#if LWIP_SO_SNDTIMEO
				case SO_SNDTIMEO:
#endif /* LWIP_SO_SNDTIMEO */
#if LWIP_SO_RCVTIMEO
				case SO_RCVTIMEO:
#endif /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
				case SO_RCVBUF:
#endif /* LWIP_SO_RCVBUF */
					/* UNIMPL case SO_OOBINLINE: */
					/* UNIMPL case SO_SNDBUF: */
					/* UNIMPL case SO_RCVLOWAT: */
					/* UNIMPL case SO_SNDLOWAT: */
#if SO_REUSE
				case SO_REUSEADDR:
				case SO_REUSEPORT:
#endif /* SO_REUSE */

					/* UNIMPL case SO_USELOOPBACK: */
					if(optlen < sizeof(int)) {
						err = EINVAL;
					}

					break;

				case SO_NO_CHECK:
					if(optlen < sizeof(int)) {
						err = EINVAL;
					}

#if LWIP_UDP

					if((sock->conn->type != NETCONN_UDP) ||
					        ((udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_UDPLITE) != 0)) {
						/* this flag is only available for UDP, not for UDP lite */
						err = EAFNOSUPPORT;
					}

#endif /* LWIP_UDP */
					break;

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, SOL_SOCKET, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;

		/* Level: IPPROTO_IP */
		case IPPROTO_IP:
			switch(optname) {
				/* UNIMPL case IP_HDRINCL: */
				/* UNIMPL case IP_RCVDSTADDR: */
				/* UNIMPL case IP_RCVIF: */
				case IP_TTL:
				case IP_TOS:
					if(optlen < sizeof(int)) {
						err = EINVAL;
					}

					break;
#if LWIP_IGMP

				case IP_MULTICAST_TTL:
					if(optlen < sizeof(u8_t)) {
						err = EINVAL;
					}

					if(NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
						err = EAFNOSUPPORT;
					}

					break;

				case IP_MULTICAST_IF:
					if(optlen < sizeof(struct in_addr)) {
						err = EINVAL;
					}

					if(NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
						err = EAFNOSUPPORT;
					}

					break;

				case IP_MULTICAST_LOOP:
					if(optlen < sizeof(u8_t)) {
						err = EINVAL;
					}

					if(NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
						err = EAFNOSUPPORT;
					}

					break;

				case IP_ADD_MEMBERSHIP:
				case IP_DROP_MEMBERSHIP:
					if(optlen < sizeof(struct ip_mreq)) {
						err = EINVAL;
					}

					if(NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
						err = EAFNOSUPPORT;
					}

					break;
#endif /* LWIP_IGMP */

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_IP, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;

#if LWIP_TCP

		/* Level: IPPROTO_TCP */
		case IPPROTO_TCP:
			if(optlen < sizeof(int)) {
				err = EINVAL;
				break;
			}

			/* If this is no TCP socket, ignore any options. */
			if(sock->conn->type != NETCONN_TCP)
				return 0;

			switch(optname) {
				case TCP_NODELAY:
				case TCP_KEEPALIVE:
#if LWIP_TCP_KEEPALIVE
				case TCP_KEEPIDLE:
				case TCP_KEEPINTVL:
				case TCP_KEEPCNT:
#endif /* LWIP_TCP_KEEPALIVE */
					break;

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;
#endif /* LWIP_TCP */
#if LWIP_UDP && LWIP_UDPLITE

		/* Level: IPPROTO_UDPLITE */
		case IPPROTO_UDPLITE:
			if(optlen < sizeof(int)) {
				err = EINVAL;
				break;
			}

			/* If this is no UDP lite socket, ignore any options. */
			if(sock->conn->type != NETCONN_UDPLITE)
				return 0;

			switch(optname) {
				case UDPLITE_SEND_CSCOV:
				case UDPLITE_RECV_CSCOV:
					break;

				default:
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_UDPLITE, UNIMPL: optname=0x%x, ..)\n",
					                            s, optname));
					err = ENOPROTOOPT;
			}  /* switch (optname) */

			break;
#endif /* LWIP_UDP && LWIP_UDPLITE */

		/* UNDEFINED LEVEL */
		default:
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, level=0x%x, UNIMPL: optname=0x%x, ..)\n",
			                            s, level, optname));
			err = ENOPROTOOPT;
	}  /* switch (level) */


	if(err != ERR_OK) {
		sock_set_errno(sock, err);
		return -1;
	}


	/* Now do the actual option processing */
	data.sock = sock;
#ifdef LWIP_DEBUG
	data.s = s;
#endif /* LWIP_DEBUG */
	data.level = level;
	data.optname = optname;
	data.optval = (void*)optval;
	data.optlen = &optlen;
	data.err = err;
	tcpip_callback(lwip_setsockopt_internal, &data);
	sys_arch_sem_wait(&sock->conn->op_completed, 0);
	/* maybe lwip_setsockopt_internal has changed err */
	err = data.err;

	sock_set_errno(sock, err);
	return err ? -1 : 0;
}

static void
lwip_setsockopt_internal(void* arg) {
	struct lwip_sock* sock;
#ifdef LWIP_DEBUG
	int s;
#endif /* LWIP_DEBUG */
	int level, optname;
	const void* optval;
	struct lwip_setgetsockopt_data* data;

	LWIP_ASSERT("arg != NULL", arg != NULL);

	data = (struct lwip_setgetsockopt_data*)arg;
	sock = data->sock;
#ifdef LWIP_DEBUG
	s = data->s;
#endif /* LWIP_DEBUG */
	level = data->level;
	optname = data->optname;
	optval = data->optval;

	switch(level) {

		/* Level: SOL_SOCKET */
		case SOL_SOCKET:
			switch(optname) {

				/* The option flags */
				case SO_BROADCAST:

				/* UNIMPL case SO_DEBUG: */
				/* UNIMPL case SO_DONTROUTE: */
				case SO_KEEPALIVE:
					/* UNIMPL case SO_OOBINCLUDE: */
#if SO_REUSE
				case SO_REUSEADDR:
				case SO_REUSEPORT:
#endif /* SO_REUSE */

					/* UNIMPL case SO_USELOOPBACK: */
					if(*(int*)optval) {
						ip_set_option(sock->conn->pcb.ip, optname);
					} else {
						ip_reset_option(sock->conn->pcb.ip, optname);
					}

					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, SOL_SOCKET, optname=0x%x, ..) -> %s\n",
					                            s, optname, (*(int*)optval ? "on" : "off")));
					break;
#if LWIP_SO_SNDTIMEO

				case SO_SNDTIMEO:
					netconn_set_sendtimeout(sock->conn, (s32_t) * (int*)optval);
					break;
#endif /* LWIP_SO_SNDTIMEO */
#if LWIP_SO_RCVTIMEO

				case SO_RCVTIMEO:
					netconn_set_recvtimeout(sock->conn, *(int*)optval);
					break;
#endif /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF

				case SO_RCVBUF:
					netconn_set_recvbufsize(sock->conn, *(int*)optval);
					break;
#endif /* LWIP_SO_RCVBUF */
#if LWIP_UDP

				case SO_NO_CHECK:
					if(*(int*)optval) {
						udp_setflags(sock->conn->pcb.udp, udp_flags(sock->conn->pcb.udp) | UDP_FLAGS_NOCHKSUM);
					} else {
						udp_setflags(sock->conn->pcb.udp, udp_flags(sock->conn->pcb.udp) & ~UDP_FLAGS_NOCHKSUM);
					}

					break;
#endif /* LWIP_UDP */

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;

		/* Level: IPPROTO_IP */
		case IPPROTO_IP:
			switch(optname) {
				case IP_TTL:
					sock->conn->pcb.ip->ttl = (u8_t)(*(int*)optval);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_IP, IP_TTL, ..) -> %d\n",
					                            s, sock->conn->pcb.ip->ttl));
					break;

				case IP_TOS:
					sock->conn->pcb.ip->tos = (u8_t)(*(int*)optval);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_IP, IP_TOS, ..)-> %d\n",
					                            s, sock->conn->pcb.ip->tos));
					break;
#if LWIP_IGMP

				case IP_MULTICAST_TTL:
					sock->conn->pcb.udp->ttl = (u8_t)(*(u8_t*)optval);
					break;

				case IP_MULTICAST_IF:
					inet_addr_to_ipaddr(&sock->conn->pcb.udp->multicast_ip, (struct in_addr*)optval);
					break;

				case IP_MULTICAST_LOOP:
					if(*(u8_t*)optval) {
						udp_setflags(sock->conn->pcb.udp, udp_flags(sock->conn->pcb.udp) | UDP_FLAGS_MULTICAST_LOOP);
					} else {
						udp_setflags(sock->conn->pcb.udp, udp_flags(sock->conn->pcb.udp) & ~UDP_FLAGS_MULTICAST_LOOP);
					}

					break;

				case IP_ADD_MEMBERSHIP:
				case IP_DROP_MEMBERSHIP: {
					/* If this is a TCP or a RAW socket, ignore these options. */
					struct ip_mreq* imr = (struct ip_mreq*)optval;
					ip_addr_t if_addr;
					ip_addr_t multi_addr;
					inet_addr_to_ipaddr(&if_addr, &imr->imr_interface);
					inet_addr_to_ipaddr(&multi_addr, &imr->imr_multiaddr);

					if(optname == IP_ADD_MEMBERSHIP) {
						data->err = igmp_joingroup(&if_addr, &multi_addr);
					} else {
						data->err = igmp_leavegroup(&if_addr, &multi_addr);
					}

					if(data->err != ERR_OK) {
						data->err = EADDRNOTAVAIL;
					}
				}
				break;
#endif /* LWIP_IGMP */

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;

#if LWIP_TCP

		/* Level: IPPROTO_TCP */
		case IPPROTO_TCP:
			switch(optname) {
				case TCP_NODELAY:
					if(*(int*)optval) {
						tcp_nagle_disable(sock->conn->pcb.tcp);
					} else {
						tcp_nagle_enable(sock->conn->pcb.tcp);
					}

					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_NODELAY) -> %s\n",
					                            s, (*(int*)optval) ? "on" : "off"));
					break;

				case TCP_KEEPALIVE:
					sock->conn->pcb.tcp->keep_idle = (u32_t)(*(int*)optval);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPALIVE) -> %"U32_F"\n",
					                            s, sock->conn->pcb.tcp->keep_idle));
					break;

#if LWIP_TCP_KEEPALIVE

				case TCP_KEEPIDLE:
					sock->conn->pcb.tcp->keep_idle = 1000 * (u32_t)(*(int*)optval);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPIDLE) -> %"U32_F"\n",
					                            s, sock->conn->pcb.tcp->keep_idle));
					break;

				case TCP_KEEPINTVL:
					sock->conn->pcb.tcp->keep_intvl = 1000 * (u32_t)(*(int*)optval);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPINTVL) -> %"U32_F"\n",
					                            s, sock->conn->pcb.tcp->keep_intvl));
					break;

				case TCP_KEEPCNT:
					sock->conn->pcb.tcp->keep_cnt = (u32_t)(*(int*)optval);
					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, TCP_KEEPCNT) -> %"U32_F"\n",
					                            s, sock->conn->pcb.tcp->keep_cnt));
					break;
#endif /* LWIP_TCP_KEEPALIVE */

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;
#endif /* LWIP_TCP*/
#if LWIP_UDP && LWIP_UDPLITE

		/* Level: IPPROTO_UDPLITE */
		case IPPROTO_UDPLITE:
			switch(optname) {
				case UDPLITE_SEND_CSCOV:
					if((*(int*)optval != 0) && ((*(int*)optval < 8) || (*(int*)optval > 0xffff))) {
						/* don't allow illegal values! */
						sock->conn->pcb.udp->chksum_len_tx = 8;
					} else {
						sock->conn->pcb.udp->chksum_len_tx = (u16_t) * (int*)optval;
					}

					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_UDPLITE, UDPLITE_SEND_CSCOV) -> %d\n",
					                            s, (*(int*)optval)));
					break;

				case UDPLITE_RECV_CSCOV:
					if((*(int*)optval != 0) && ((*(int*)optval < 8) || (*(int*)optval > 0xffff))) {
						/* don't allow illegal values! */
						sock->conn->pcb.udp->chksum_len_rx = 8;
					} else {
						sock->conn->pcb.udp->chksum_len_rx = (u16_t) * (int*)optval;
					}

					LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_UDPLITE, UDPLITE_RECV_CSCOV) -> %d\n",
					                            s, (*(int*)optval)));
					break;

				default:
					LWIP_ASSERT("unhandled optname", 0);
					break;
			}  /* switch (optname) */

			break;
#endif /* LWIP_UDP */

		default:
			LWIP_ASSERT("unhandled level", 0);
			break;
	}  /* switch (level) */

	sys_sem_signal(&sock->conn->op_completed);
}

int
lwip_ioctl(int s, long cmd, void* argp) {
	struct lwip_sock* sock = get_socket(s);
	u8_t val;
#if LWIP_SO_RCVBUF
	u16_t buflen = 0;
	s16_t recv_avail;
#endif /* LWIP_SO_RCVBUF */

	if(!sock) {
		return -1;
	}

	switch(cmd) {
#if LWIP_SO_RCVBUF

		case FIONREAD:
			if(!argp) {
				sock_set_errno(sock, EINVAL);
				return -1;
			}

			SYS_ARCH_GET(sock->conn->recv_avail, recv_avail);

			if(recv_avail < 0) {
				recv_avail = 0;
			}

			*((u16_t*)argp) = (u16_t)recv_avail;

			/* Check if there is data left from the last recv operation. /maq 041215 */
			if(sock->lastdata) {
				struct pbuf* p = (struct pbuf*)sock->lastdata;

				if(netconn_type(sock->conn) != NETCONN_TCP) {
					p = ((struct netbuf*)p)->p;
				}

				buflen = p->tot_len;
				buflen -= sock->lastoffset;

				*((u16_t*)argp) += buflen;
			}

			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_ioctl(%d, FIONREAD, %p) = %"U16_F"\n", s, argp, *((u16_t*)argp)));
			sock_set_errno(sock, 0);
			return 0;
#endif /* LWIP_SO_RCVBUF */

		case FIONBIO:
			val = 0;

			if(argp && *(u32_t*)argp) {
				val = 1;
			}

			netconn_set_nonblocking(sock->conn, val);
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_ioctl(%d, FIONBIO, %d)\n", s, val));
			sock_set_errno(sock, 0);
			return 0;

		default:
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_ioctl(%d, UNIMPL: 0x%lx, %p)\n", s, cmd, argp));
			sock_set_errno(sock, ENOSYS); /* not yet implemented */
			return -1;
	} /* switch (cmd) */
}

/** A minimal implementation of fcntl.
 * Currently only the commands F_GETFL and F_SETFL are implemented.
 * Only the flag O_NONBLOCK is implemented.
 */
int
lwip_fcntl(int s, int cmd, int val) {
	struct lwip_sock* sock = get_socket(s);
	int ret = -1;

	if(!sock || !sock->conn) {
		return -1;
	}

	switch(cmd) {
		case F_GETFL:
			ret = netconn_is_nonblocking(sock->conn) ? O_NONBLOCK : 0;
			break;

		case F_SETFL:
			if((val & ~O_NONBLOCK) == 0) {
				/* only O_NONBLOCK, all other bits are zero */
				netconn_set_nonblocking(sock->conn, val & O_NONBLOCK);
				ret = 0;
			}

			break;

		default:
			LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_fcntl(%d, UNIMPL: %d, %d)\n", s, cmd, val));
			break;
	}

	return ret;
}

#endif /* LWIP_SOCKET */
